Resistance unit



infested' Iviu. 4, 1941 misIs'raNca Ui'vrr penale F.- nuuags, Fair Lawn, N. J., assigner ee Hardwick, Hindle, Inc., Newark, N. J

Application December zo, 1939, sei-iai No. 310,155

'rhisinveniion rentes' te av resistance unit and .especially one ci the wound ceramic type; that is,

one having a core ortorm otlceramic material on which .the resistance winding is arranged, and

after the windingis ii.p1.'il iedthe same'is covered with. a coating of vitreous material andv baked,.

the windingl ybeing provided .with suitable' terminals by which electrical connection' maybe made to the resistance unit.

The present invention has for its principal ob`- ject the provision of an improved means for mounting the resistance unit whereby the mountend of the core in opposite directions with respect to the opposite ends of the core. The reason for this angularly positioned lug is to takecare of the variations in the length of the core I,- asin the manufacture of the core thislengthmay vary as 5 much as or more. i

The lugs 3 are preferably located so that the lbases'oi the-lugs 3 atthe notch 5 will-come a short distance inside thevplaneoithe ends of the core l asshown at the left-hand end of Figl0 ing -is of such a type that the strains on the unit are reduced to a minimum' and at the same time are distributed 'along the length ofthe unit in stead of being, concentrated at the ends as is customary in most resistance devices of thiskind with which Iamiamiliar.

Another object of my invention is to provide a u nit assembly which lends itself :to stacking the unit in an eilicient and compact manner.

Another object of my invention is'to provide an assembly unit which is rugged in construction #and cheap to manufacture.

Other objects will be discerned by one familiar with these devices, from a study ot the annexed drawing, wherein; I

Figure 1 is aA plan view of my improved type or resistance unit.

Figure 2 is a side view or the device iocking at the side opposite the terminals."

Figure a is an end view or the device shawn in Figure 1.

- Figure 4 is a fragmentary view of a modiiled' form of mountingst'rip. Q

Figure Sis a iragmentaryvview oi' a furthermodined form of mounting strip. 'FigureisasideviewofFigure.

Figure 7 is a plan view ot a modincation of the mounting strip shown in Figure 1.

Figure 8 shows the method o! -assemblingthe resistance unitin a stack.

In' the various views, wherein like numbers reure 1, ca1cu1ated on a theoretically correct length of the core. Should the length of the core i vary, for example, over its calculated length, it will overlap a certain portion of the lugs 3.A However, there will be some part of the -lugs which is not l5 covered by the core, and this extending end or ends are, after the strip 2 has been slipped into the hollow core, bent or displaced out of the plane 'oi the strip as indicated in Figures l and 2, thereby lockingthe core I securely in position in the 20 strip 2, 4after which the hollow mounting studs 6 are fastened to the extremities of the strip 2 in any satisfactory manner as by spinning over, at

1, their properly formed ends.

As shown in Figure 4, the metallic strip 2 may 25 have formed at one end, abutments 8 which overlap the end of the core i while the opposite end is formed with the displaceable lugs 3. The strip 2 is provided with a.hole 9 to receive a mounting stud '6.

In Figure 5 a lug or nnger III is formed in the strip 2 by cutting out a U-shapediormation Il, leaving the ilnger i0 in the plane of the lstrip 2, which nnger or lug may be bent upwardly across the face 'oi the core l after the metallic strip has 35 been inserted, ini place within vthe hollow core. Both 'ends'of the metallic strip 2 may be constructed with ngers I0, or this construction may be used with the construction shown in Figure 4.

. However, I prefer the construction of. Figure 1,

"ier to corresponding parts, I is a hollowcorezof ceramic material which is relatively` wide and thin as compared with its thickness. The hollow part of the core is also relatively wide and narrow to receive 'a' relatively thin. ilat, metallic strip 2. Asshown in Figures land 2,thestrip 2 has abutment means located at opposite ends of the core I. A'l'.'he abutment means shownin Figure 1 comprises a plurality ot lugs 3 which are formed by cutting away the material at I and i so as' to leave the lugs extending at an angle to the axis of the strip 2 and the core l, and away from the for'the reason that the lugs 3 are positioned toward the stronger pontion of the ceramic core and the bending of the lugsis not so apt to crack-or injure theends of theinsulator as the centrally located lug I0 shown in Figure 5, which-ls bent in 45 a direction at right angles to the bend oi' the. lugs 3. Of course, lthe lug 1n may be positioned to oneV side of the axial center of the strip 2 which'will partly overcomev this objection. j

For-different resistances the length o1' the core 50 lf and its winding, where the same size wire is. used, is'longer, and to cover the range dinerent lengths ormetallic strips 2 will be required. Instead of making different 'punches and dies for these various lengths o! mounting strips, I mays length to suit the requirements of thevresistance unit desired to be mounted. .Y l The resistance units may be mounted individually or they may be mounted on a boltor stud I5 fastened to a support member I 6 by passing the hollow studs 6 over the bolt I5. Since the winding carried by the core Iisprovided with terminals I'I and I8, itis very easy to connect the resistance units in series or multiple, or anyarrangement desired, by properly connecting -thel terminals I1 and|8 after :the'units have been stacked in a manner similar to that shown inl Flguref8-- From the, foregoing, it will be seen that I have provided a resistance' unit ,in which the mounting centers between the mounting studsB-may be accurately fixed without any ydirect relationfto` the location of the terminals I'I-and I8.

Y The metallic stripl 2 may'be made `of anysatis-A factory material, either magnetic or-non'mag netic, depending 'pn the requirements, and since y metal 'is a good conductor of heat, the heat is conveyed away from the interior of the vcore I better. with this metallic support than if air alone were used as the conducting means., It will also -be observed that all the mounting strains.' such as tightening up on'the vnut I8 where the units arestacked,I or equivalent :arrangement if the units are mounted individually, are applied to the metallic strip- 2 and.none,.whatever,l to the core I and its winding which is-applied after the core has been madeand..tl 1e.`.terminalsfixed to the winding, and then a-vltreous enamel coating applied and the whole balr'ehthus vforming the resistance unit per se. :The strains, if any, due to expansion and contraction under heating and cooling, are distributed along the'length of the core which has a small amount oflooseness in its mounting on the strip 2 .to take care of this expansidn and contraction of the parts, and also for ease of assembly.

Certain changes -may be made in the details without departing from'the spirit of my invention: for example, the construction shown in Figure 'I'may be varied by having a tool to receive one end of the strip t'o make the lugs 3 andv mounting holes 9. The strip may then be sheared to the right length to suit the requirements and this'sheared-ofi portion reversed and inserted in the tool for forming the opposite end.

lWhile I have shown one typeof terminal for the`windlng,` .may be varied over avwide range.

What I claim is: 1. A resistance-unit comprising a single-piece hollow core of ceramic material having a winding thereon with terminals leading therefrom, a me'- tallic member passing through the ceramic-core and having integral abutment means at opposite ends ofthe said core, the abutment means at one Vend-at least being formed at an angle to the axis of the metallic-memberfand displaced. after assembly, of thenietallicfmember and core, in a mannerto engageV the end of the core and lock the core with its winding securely on the metal member, andmeans at the extremities of the metal member for-mounting the unit on a sup-l 2. .A resistance unit comprising a single-piece hollow core of ceramic material having a winding thereon with terminals leading therefrom, means for mounting the core and winding on predetermined centers eventhough the length of the core may 'vary considerablyfor a'. given resistance unit, said means including a metallic member passing through the core and Vhaving integral abutments at opposite ends of the 'core formedat an angle to the axis of the metallicmember and displaced, after assembly of the metallic member and core. 1

in a manner'to engage the ends ofthe core of varying length for a given unit,`and means at the extremities of the metal member for mounting the unit on a support.l

' 3. A resistance unit comprising a hollow core of ceramic material with a winding thereonhaving extending'eterminals, the core being relatively Wide and thin and the hollow part being Wide and narrow, a relatively thin, flat, metallic strip located rather loosely in the hollowfcore to .allow for expansion land contraction ofthe parts, the

strip havin'g integral` abutment means at opposite ends .of the core, the abutment means atione end at least being formed at an angle to the axis of the metallic strip anddisplaced after assem-v bly ofthe core and strip in a manner to lockthe .core securely 4on the metallic strip, and means at the extremities of the strip for mounting the unit on a support.

4. A resistance unit comprising a hollow core of ceramic material with a winding thereon having extended terminals, the corebeing relatively wideand thin and -the hollow part being wide.

and narrow, a relatively thin, fiat, metallic strip located in the hollow core,the strip having inte'gral lugs located adjacent the ends of the core and formed atan acute angle to the axis of the strip and core, the lugs at one end extending in a direction away from the core end and vopposite to those at thel other end of the core.'.sad lugs -being bendable along their length so at least some portion thereof extends beyond .the end of the core and over a portion of the end surface of.

the core and in contact therewith, and meansat the ends of the strips for mounting the unit.

5. A resistance unit comprising a hollow core of ceramic material having a winding thereon l with terminals leading therefrom, the hollow part of the core being relatively-wide and narrow, a thin, metallic strip positioned in the hollowpart of the core, the strip having integral abutment lugs located adjacent .the 'ends' of the cor'e, those at one end at least being bendable across the end surface of the core and in contact therewith to lock it in-place on'the strip, and studs attached to-the extremities 'of the strip for mounting 'the unit individually as well 'as in a stack.

.6. In a resistance unit of the wound ceramic type having a hollow core, means for mounting the unit comprising a metallic strip passing through the core, the strip having .integral lugs formed at an acute angle on the sidesof the strip adjacent .the ends of the core 'and extending away froml the core ends, the -lugs being of a -length and positionedl so someportion of them is overlapped by the core while .the unlapped portion is bent across a portion ofthe end of the COTS.

. 7. Means for mounting individual resistance units of'diiferent lengths and res tance values wherein each unit has a single-'pi ce hollow core of ceramic material with a winding directly fixed thereon; said means comprising a relatively thin,

vflat metallic strip passing through the core, the

strip havingv two similar end sections used .for all units and interconnected by a single plain section having an initially separate length to suit the resistance unit required to be mounted, each end section having means .to `engage the ends of the core', the means at onelend at least being bendable into engaging position with the core after the said strip has been inserted through the core, and further means for mounting the core` and strip assembly.

` 8. In a resistance unit of the Wound ceramic type having an integral hollow core, means for the metal strip-and having integral means at its opposite ends for engaging the ends of the core j said means, at least'at one end,being angularly CERTIFICATE oF ccm'REc'i'cIolN. v Patent No. 2,235,150. l March )4, 19141.

' DONALD F. HASTINGS. A It is hereby certified that error epperein tbe prntedspecification of the above numbered patent requiring correction as follows; Page 2, second colmnn, line 5T, claim I+, for* the word "extended read-Next ending--g line Thy-'claim 6, after "c0re' and before thro period insert --and in coniact therewith-n.; and -tbat the said Letters Patent-should be* 'read with this correction therein bhat -the same 'moy conform to the rec-ord of the ase in the Patent office.

signed and sealed this 3th das?, of Apr-11, -AQ D. 19M.

I Henry Van Arsdale,

(Seal)l Acting Commissioner of Patente.'r

- 4 CERTIFICATE oF' coRnEcTIoN. 4 v patent No. 2,235,150. vmmh LL, 19m.

' DONALD F. HASTINGS.

` It is hereby certified vthat error appears in the printed'specification ofthe above numbered patent requiring `cc-:lzrrecixlon as follov-vs-r Page 2, second column, line 5T, claim h, for the word'v "e xtfended" read-extending--g line 'b-"claim 6, after "core" and before theperiod insert --and in conf `tact therewith-.; and -that the said 'Letters Patentshonld bei read with this correction therein that the same may conform tothe record of the case in the Patent Office. A Y

signed and eealdthis 8th dai of Apr11,-A. D. 19ml l Henry van Arsdale, v (Seal). I Acting Commi'sio'ler of Patente.' 

